Charles Greely Abbot, 1872–1973, was an American astrophysicist, born in Wilton, N.H. He was acting director in 1896 and director in 1907 of the astrophysical observatory of the Smithsonian Institution; he was secretary of the institution from 1928 to 1944 when he became a research associate. Samuel Pierpoint Langley, his predecessor, initiated many of his research studies. He completed the mapping of the infrared solar spectrum and carried out systematic studies of variation in solar radiation, its relation to the sunspot cycle, and its effect on weather variation. He also studied the nature of atmospheric transmission and absorption. Abbot perfected various standardised instruments now widely used for measuring the sun's heat, and he invented devices utilizing solar energy. Abbot graduated from the Massachusetts Institute of Technology (MIT) in 1894. He wrote The Sun (1911). An astrophysicist is a person whose profession is astrophysics. ... Categories: Stub | Astronomical observatories ... The Smithsonian castle, as seen through the garden gate. ... Samuel Pierpont Langley (August 22, 1834 in Roxbury, Massachusetts near Boston, – February 27, 1906, Aiken, South Carolina) was an American astronomer, physicist, inventor, aeronautics pioneer and aircraft engineer. ... Image of a small dog taken in mid-infrared (thermal) light (false color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than visible light, but shorter than microwave radiation. ... The noun spectrum (plural: spectra) has a variety of meanings. ... 400 year sunspot history A sunspot is a region on the Suns surface (photosphere) that is marked by a lower temperature than its surroundings, and intense magnetic activity. ... Composite satellite image showing the progress of a hurricane weather system approaching the east coast of America Weather comprises all the various phenomena that occur in the atmosphere of a planet. ... Atmosphere may refer to: a celestial body atmosphere, e. ... Absorption has a number of meanings: In physics, absorption is a process in which particles of some sort encounter another material and are taken up by or even disappear in it. ... A sun is the star at the center of a solar system. ... Solar power describes a number of methods of harnessing energy from the light of the sun. ... The Massachusetts Institute of Technology, or MIT, is a research institution and university located in the city of Cambridge, Massachusetts directly across the Charles River from Bostons Back Bay district. ... 1894 was a common year starting on Monday (see link for calendar). ...